1. Field of the Invention
Many proposals have been made heretofore to construct permanent stations in outer space which will include various structures that must be assembled either by human astronauts or by employing remotely-controlled robots.
Accordingly, the present invention pertains to new and improved fastener devices which are cooperatively arranged for easily and quickly connecting and disconnecting various subassemblies or elements that are disposed in outer space. In particular, this invention relates to new and improved quick connect fastener devices which can be effectively used in outer space by either astronauts or robots for securely intercoupling various structural members as well as quickly joining various components which are to be assembled and, as needed, subsequently disassembled with minimum effort.
2. Background Art
At present, it is proposed to construct the NASA space station by assembling a plurality of prefabricated tubular truss members into predetermined spatial configurations. The truss members are coupled to one another by fastener devices which are mounted on the ends of the structural members and arranged to be releasably attached to so-called "node-point" fittings. These fastener devices typically include a male projection which is adapted to be releasably secured within a selected socket on one of these node-point fittings. To . facilitate the assembly of the truss members into different configurations, the sockets are spatially disposed around the node-point fittings in a predetermined pattern allowing the truss members to be positioned in various orientations relative to one another and coupled to one another by means of the node-point fittings.
Those skilled in the art will realize that any type of fastener which is to be utilized for assembling structures in outer space must be capable of being easily and quickly installed by personnel working under the adverse conditions of outer space. Moreover, once the respective components of a given structure have been intercoupled, it is absolutely essential that these components remain securely locked to one another until the structure is disassembled. It will also be appreciated that it may be necessary in the future to use remotely-controlled devices for assembling a variety of components in space. Thus, any fastener system which is to be utilized in space either for erecting structures or for intercoupling various devices must employ a relatively uncomplicated actuation mechanism which is capable of being readily operated by astronauts using simple manual tools or by remotely-controlled robotic assembly devices.
One particularly useful fastener system which has been proposed heretofore for assembling structures in outer space is disclosed in U.S. Pat. No. 4,763,459. The node-point fittings shown in that patent are formed as hollow spherical shells respectively having a plurality of spatially-disposed outwardly-facing openings into which tubular inserts are threaded. Each of these fastener devices has a forwardly projecting multi-fingered collet which is inserted into one of the tubular inserts and expanded for releasably locking the fastener to that node-point fitting. In this manner, with these fasteners mounted on the opposite ends of tubular truss members, the truss members can be releasably coupled to node point fittings to assemble structures of different configurations in outer space with a minimum of effort.
Another fastener of particular interest is shown in U.S. Pat. No. 4,998,842 where a toggle linkage mechanism is employed for advancing a collet with normally-contracted fingers into an opening in a spherical node-point fitting. Once enlarged shoulders on the ends of the collet fingers have passed through the opening, the continued operation of the toggle mechanism expands the collet for engaging those enlarged shoulders against the internal wall of the hollow node-point fitting. Biasing means are also provided for retaining the collet fingers in their expanded position.